Earth boring drill



July 7, 1936.

c. E. REED EARTH BORING DRILL Filed May 25, 1932 4 Sheets-Sheet 1 C lanence Ell feed,

July 7, 1936. c, E. EED' 2,047,112

EARTH BORING DRILL Filed May 23, 1932 4 Sheets-Sheet 2 Clarence L. Reed,

, I J 4 %wy 7% E 7 July 7, 1936. c REED 2,047,112

EAR-TH BORING DRILL File i May 23, 1952 4 Sheets-Sheet 3 July 7, 1936- 1 c. E. REED 2,047,112

EARTH BORING DRILL Filed May 25, 1932 4 Sheets-Sheet 4 Clanence EReed,

Patented July 7, 1936 UNITED STATES PATENT OFFICE EARTH BORING pans.

Application May 23, 1932, Serial No. 613,042

. 12 Claims.

The invention concerns a rotary drill apparatus having a bit head with a removable roller cutter unit or assembly.

One object of the invention is to provide a 6 roller cutter unit in which the roller cutter spindles are mounted in said-unit to be supported at one end thereby, the other ends of said spindles being supported in the bit head.

Another object of the invention is to mount 10 the roller cutter spindles removably in the body of the unit so that by removing the unit from the bit head the roller cutter or cutters with its spindle or spindles can be removed from the body of the unit and replaced by a new spindle and cutter or cutters.

Other objects of the invention will appear from the following specification.

In the drawings-- Figure 1 is a-vertical section of the bit head and 20 cutter assembly.

Fig. 2 is a detail view of part of the bit head looking from the center line of Fig. 1 rightward.

Fig. 3 is a front view of the body member or carrier for the roller cutters. 25 Fig. 4 is a plan view of Fig. 3.

Fig. 5 is a view of Fig. 3 looking towards th left.

Figs. 4a and 5a are modifications. Fig. 6 is a vertical sectional view of another form of bit head and roller cutter unit.

' Fig. '7'is a plan view of a section on line 1-1 of Fig. 6.

.Fig. 8 is a vertical section of the bit head of Fig. 6 a quarter turn from said Fig. 6.

Fig. 9 is a front view of the body or roller cutter carrier member o'fthe cutter unit. Fig. 10 is a plan view of Fig. 9.

Fig. 11 is a side view of Fig. 9 looking towards the left.

at In having an internally threaded upper end for attachment tov the drill pipe. It has a central bore II for the downward passage of flushing fluid. It has a recess l2 in its lower end of 45 substantially cylindrical form to receive the upper cylindrical end 13 of the body or carrier of the roller cutter unit. Below the cylindrical recess I2 the recess flares outwardly and down- 1 seats l at their lower ends and on the inner inclined faces M of the depending walls Ma.

' there are recesses l5, surrounding the notches I5.

55 The recess defined'by the walls is open later- Referring to Figs. 1 to 5, the bit head is shown ally of the bit head, it being understood that the lower part of the bit head is substantially oblong in horizontal cross-section, the length of the cross-section being indicated in Fig. 1 and the width of this lower part being indicated in Fig. 2. 5 It will be noted also that the notches it in the depending end walls M are in line with each other or, in other words, their centers lie in the same vertical plane passing through the axis of the bit head from end to end thereof.

The roller cutter unit, besides the cylindrical portion it above mentioned, comprises a body i'i connected with the said cylindrical portion by arms, lugs, or wings it extending up therefrom on each side. This body it is provided with a socket it on each side adapted to receive the inner ends of roller cutter spindles"al-'-b. This body member it is of general triangular form as viewed in Figs. 1 and 3-, and the axes of the sockets diverge upwardly so that the spindles, when in place, as in Fig. 1, will incline upwardly and outwardly so that their outer ends will seat in the notches or open sockets 15 at thelower ends of the depending end walls of the bit head and will bear against the solid metal of the depending walls 14 at the upper-ends of said notches. Each spindle is provided with a flange or head member formed integrally therewith or permanently afixed thereto and lying a short distance from the free end of said spindle. These flanges or heads are of a form to fit into the recesses It in the end walls l4 and adjacent the notches l5, and they contact with the upper walls of these recesses at 2| so as to take the upward thrust imposed upon the cutter assembly when at work, said thrust being taken in part by the extreme end portion of the spindle bearing against the upper wall of the notch It. The roller cutters are indicated at 22, and they may be of any suitable form. They are toothed to enter the formation and cut and break it up.

There are roller bearings 23 between the cutters and their spindles.

There is a washer 24 welded to the spindle at 25 and when two roller cutters are used on the same spindle spacing washers are employed as at 26. The inner ends of the spindle preferably simply rest in the sockets l9 of the body portion I! of the roller cutter unit.

The washers slip into recesses 24a in th central block'or body I la.

The rolier cutter unit is held to the bit head byv tapered bolts 21. passing through openings 28 in projections 29 of the bit head on their lateral faces and through openings 30 in the 55 projections i8 of the roller cutter unit,- which projections, when the parts are assembled, lie alongside the parts 23 of the bit head. The upper ends of the projections or arms [8 of the cutter unit do not bear upon the shoulders 3! on the bit head at the upper ends of the parts 29 of said bit head. The upthrust is taken by the bolts and the bit head. Upthrust is also taken by the central cylindrical portion l3 of the roller cutter unit which, as shown in Fig. 1, at its upper end bears upon the ring 32 seated in the bit head. The cylindrical part l3 of the roller cutter unit has a central bore 33 for the flushing fluid which is distributed through openings 34, 35, through the bottom wall 36 of the cylindrical portion of the carrier. The cylindrical part may be integral with the projections or arms l8, or it may be a separate part resting between the two arms l8, see Figs. 4a and 5a.

The cutters are assembled on the spindles by positioning them at one side against the heads or flanges 20, the roller bearings are slipped into place, and also the washers, and then the end washers may be welded to the spindle so that the whole assembly of spindle, cutter or cutters, washers and roller bearings may be handled as one body. This body is now placed in connection with the part i! of the carrier by slipping the inner ends of the spindles into the sockets IQ of said triangular part i1 and the whole unit is now ready to be inserted into the bit head in the relation shownin Fig. 1, both spindles inclining upwardly and outwardly. All upthrust is distributed into the head and the arrangement of the inclined spindles and body of the carrier is such that a transverse strut effect is secured in the form of an inverted arch, said arch formation being supported at its ends by the ends of the spindles bearing in the end walls of the head and said arch formation at its central portion sustaining upthrusts by connection of the central body portion I! with the bit head through the upwardly extending arms I8 and through the central cylindrical portion I3 of the roller cutter unit. The flanges 20 at their sides may be flattened to bear on the straight sides [6a of the recess IE to take lateral thrusts and said lateral thrusts are also taken by the arms l8 and by the cylindrical portion l3 of the body of the roller cutter unit. The flanges 20 may be eccentric to axis of spindle a or b, in which case .the part 2| would correspond. These eccentric parts assist ininsuring the correct placement of the spindle within th bit head as shown, so that the bevelled outer ends of the spindle and the spindle enlargements lie in their intended vertical planes within the lateral extremity of the roller cutters and will not scrape the wall of the hole.

In Figs. G to 11 inclusive a form of the invention is shown embodying the general principles involved in the form of apparatus above set forth, but differing in detail and in the addition of certain features.

The bit head in this form has a bottom wall portion 36a. provided with a central port 35a for flushing fluid and with other ports 340. all in the same vertical plane extending through the axis of the drill and from end to end of the bit head. This bit head, like that first described, is longer than wide, see Fig. '1. Flushing fluid ports 31 also extend from the central bore of the bit head and incline outwardly and downwardly through the arms or lugs 2941 at the lateral sides of the bit head. These projections or lugs 29a have the bolt holes 30a for the bolts 210 which hold the roller cutter unit to the bit head. These bolts 21a may be plain cylindrical members instead of tapered as in the form first described. In this form also the body I'la of the roller cutter carrier is of general triangular form. It is recessed at 38 to receive a roller cutter 22a which cuts an area within the zone cut by the inclined roller cutters 22.

This roller cutter is arranged on a horizontal spindle 0 having its ends supported in the body member I'la.

In this form, like in that first described, all the roller cutters are arranged with their axes in the same central vertical plane extending from end to end of the apparatus.

The thrusts are taken substantially as in the first form. In the present modification the central body portion l'la of the roller cutter carrier has an upward extension 39 which has a flat face 39a bearing on a corresponding face 40 on the bit head. Upward thrust is taken from this projection by the bearing surface 40 on the head. The bottom wall 360. of the bit head at its lower part projects downwardly substantially at its center as at 4|. It presents downwardly converging wall portions, the inclines conforming substantially to the inclined upper sides of the roller cutter. These inclined parts provide for the direction of the flushing fluid. There is a port llb through the upper part of the roller cutter carrier to direct flushing fluid to the roller cutter 22a. The body 11a of the roller cutter unit has side grooves or recesses l'lc. These recesses receive the arms 29a of the bit head, and the upwardly projecting arms No of the cutter unit flt in the recesses 29b alongside of the arms-or projections 29a so that we have an interlocking construction by arms on the cutter unit fltting re cesses in the bit head and the bit head having projections fitting in recesses He in the cutter unit.

Where features of one form are adapted for use in the other form, said forms are to be regarded as embodyingsaid features.

It is known to be old in the art to use a washer or wear plate between the face of the inclined wall of a bit head and the side ,cutter and such washers are held in' various ways against rotation. It is common to all of them to serve the purpose for a limited time. The nature of the operating loads and thrusts on an inclined side cutter are such that the tendency is to tip the upper part of the cutter towards the bit axis and push the lower part of the cutter towards the side of the bit, resulting in concentration of heavy loads on the lower part of the washer. Owing to the inclined wall of the bit head terminating in a mere edge, such washers have no substantial support below the spindle and as the wear of the'cutter on its spindle accumulates the working loads and thrusts break the washer. Often the pieces fall out of the asesmbly, allowing the cutter to move out of position and force the early withdrawal of the assembly from the bore hole. If the washer only cracks it often locks the cutter against rotation. A spindle carrying an enlargement similar to 20 eliminates washers and the trouble incident thereto and greatly prolongs the life of the cutter assembly. In this invention the depending wall of the bit head is cut away by a notch and seat recess formed in the extremity of the depending wall, the notch forming a bearing for the projecting end of the spindle and the seat recess forming a bearing for the enlarge- 75 and rigidly seated on the surface 2!], in other words, as will be seen from the drawings and this specification all loads are carried up into the thick part of the bit head. The part it is made thick and heavy and extends inward past the wall of bit head and downward below the extremity of the inclined wall of the bit head and outwardly beyond the line of the vertical side of the bit head, it replaces the thin extremity of the wall of the bit head. This part it as shown is made thick and heavy and will not bend or break or otherwise fail in service. All outward or spreading thrusts of the cutter are carried by this part it up into the thick, heavy part of the bit head and the cutter is held firmly in its position until the cutter teeth are worn out.

I claim:

1. An earth boring apparatus comprising a bit head having a depending wall, said wall having seat recesses and notches, both opening downwardly, a roller cutter unit comprising roller cutters and spindles for the roller cutters and a carrier arranged between said spindles and to which the inner ends of the roller cutter spindles are removably connected, upper end portions of said carrier bearing in recesses in the sides of the body of the bit head, and means for securing the cutter carrier to the outer sides of the body of the bit head and at a level above that of the roller cutters, the spindles having enlargements inwardly from their outer ends,

.said enlargements and outer spindle ends fitting said seat recesses and notches, said bit head having means for securing it to the drill stem,

substantially as described.

2. A bit head for roller cutter earth boring drills having a recess at its lower end defined by downwardly and outwardly inclined opposed end walls having notches in their lower edges to a'fford bearings for roller cutter spindles and seat recesses in the inclined walls at said notches to afford bearings for the roller cutter assembly, a projection at each side of the bit head a quarter turn from the notches with a recess adjacent each projection to'interengage portions of the roller cutter assembly, the said bit head being substantially oblong in horizontal'cross-section with the notches in the same plane passing through the vertical axis of the head and with the projections and adjacent recesses at the long sides, substantially as described.

3. In combination a roller cutter spindle having a non-concentric member fixed thereon, a bit head having-a bearing in its wall for said roller cutter spindle with a recess non-concentric relative to said bearing for receiving said -nonconcentric member on. the spindle, and a' carrier for said spindle having a socketto removably receive said spindle, said non-concentric memberextending laterally beyond and also below said bit head to take operatingloads and wear, the non-concentric coacting surfaces on the bit head and spindle preventing rotation of the spindle, substantially as described.

4. A roller cutter assembly for insertion into a bit head of an earth boring drill comprising a carrier member, roller cutter spindles, said carrier being arranged between the adjacent ends incline upwardly and outwardly with their axes in radial planes and having their outer ends adapted to fit in bearings in the bit head, said cutter assembly being in the general form of an inverted arch in vertical cross section, and having arms lying in vertical plane substantially intermediate the radial planes in which the axes of the spindles lie.

5. A roller cutter assembly according to claim 4 in which the spindles are provided with enlargements between their ends affording thrust bearing means to engage the wall of a bit head to prevent longitudinal displacement of the spindles, substantially as descri. v

6. A roller cutter assembly according to claim 4 in which each spindle has a non-concentric flange to fit a seat recess in a bit head to hold the spindle against rotatiye and longitudinal movement,

' and projects laterally beyond and below the exwardly and outwardly, said walls defining a downwardly opening recess to detachably receive a roller cutter carrier, said depending walls each having anotch and an adjacent seat recess both opening at the bottom edge of the depending wall and presenting bearing surfaces at their upper ends, each seat recess being larger than the notch and presenting also a downwardly and outwardly inclined face, a .roller cutter carrier fitting within the recess of the bit head, said carrier having seat recesses opening upwardly and outwardly to receive therein cutter spindles, spindles for the roller cutters each having its inner end positioned in a seat recess ofthe carrier from which the spindle projects upwardly and outwardly in a radial plane, the outer end of each spindle engaging the bearing surface of one of said notches, said spindles having enlargements adjacent their outer ends engaging the bearing surfaces and the bearing faces of the seat recesses in the bit head to sustain the longitudinal and lateral thrusts of the spindles, and roller cutters mounted on said spindles, said enlargements replacing a substantial portion of the bit head removed by the seat recesses therein, and said enlargements extending laterally beyond and also below said depending wall, taking roller cutter end thrusts and relieving the lower extremity of the depending wall of loads and friction wear,

8. In an earth boring apparatus, a bit head having a depending wall, said wall having a seat recess'on its inner face, a roller cutter and spindle assembly removably mounted on the under side of the bit head, said assembly comprising a spindle having roller bearings and roller cutters thereon and exteriorly of the cutter an enlargement of the spindle extending across and beyond the ends of the roller bearings constituting end thrust receiving means, said enlargement fitting within said seat recess and bearing on the wall of said seat recess.

9. In combination in an earth boring drill, a bit head having a depending wall with'a downwardly opening notch at the lower end and a seat recess in its inner face also opening downwardly adjacent and communicating with the open notch and larger than said notch, a roller cutter spindle having a free end seated in the notch and an integral enlargement in the seat recess, a roller cutter on the spindle, roller bearings between the spindle and roller cutter having their outer ends bearing on said enlargement, carrier means for the spindle, and means for securing the same to the bit head, substantially as described.

10. An earth boring drill according to claim 9 in which the enlargement on the spindle is located wholly exteriorly to the roller cutter.

- 11. A spindle for a roller'cutter of an earth boring drill having near and spaced inwardly from one end an integral enlargement of nonconcentric shape relative to the axis of said spindle, said end beyond the enlargement having its end face lying in a plane at an acute angle to the axis of the spindle, the spindle from said enlargement to the more remote end thereof being of plain cylindrical form throughout, substantially as described.

longitudinal displacementby said integral en- 10 largement and aflixed flange, the end portions oi the spindles beyond the said enlargement and flange being adapted to engage on a drill structure, said enlargement and afiixed washer and the adjacent spindle ends constituting the sole 1 bearing means for mounting in a bit head struc- I ture.

CLARENCE E. REED. 

